A two-part hair cosmetic material comprises a first agent containing an alkali agent such as ethanolamine, a carbonate and ammonia, and a second agent containing an oxidizing agent such as hydrogen peroxide. Both the agents are mixed together immediately before use to give a hair cosmetic material, and the hair cosmetic material is applied to the hair to bleach or dye the hair.
Among the above-mentioned alkali agents, ethanolamine may have defects such as hair damage and skin irritation since it is very persistent on the hair. Further, since a carbonate is weak in the effect of enhancing bleaching power or hair dyeing power due to hydrogen peroxide, bright coloration of the hair may become insufficient. To the contrary, since ammonia does not remain in the hair, and further can sufficiently enhance bleaching power or dyeing power due to hydrogen peroxide, it is most generally used in a two-part hair cosmetic material for bleaching or dyeing.
However, ammonia may emit a peculiar irritating smell that gives discomfort to a user when a first agent and a second agent are mixed together, or when a hair cosmetic material obtained by mixing both the agents together is applied to the hair. Particularly, when the blending amount of ammonia is increased in order to sufficiently bleach or dye the hair, a more overpowering irritating smell may be emitted to give discomfort to the user.
In order to solve these problems, a variety of methods have been reported. For example, a composition which reduces an irritating smell due to ammonia is known, which is obtained by incorporating an alkali agent into a liquid crystal structure of a hair cosmetic material (JP-A-2003-40750 and JP-A-2004-189638).
However, in the conventional composition utilizing a liquid crystal structure, there is a problem that the degree of freedom of formulation is restricted in order to attain a stable emulsion state and reduce an irritating smell due to ammonia. Particularly, there may arise a problem that, when the viscosity of the hair cosmetic material is reduced in order to provide a hair cosmetic material which can be easily spread on the whole hair uniformly and which has good combability (comb through property) when it is adapted to the hair again during the time after the application, an irritating smell due to ammonia cannot be reduced, for example. Further, there may arise a problem that an irritating smell due to ammonia becomes further stronger in a case where strong bleaching power or dyeing power is required and ammonia in an amount sufficient for the desired bleaching or dyeing effect is added to the hair cosmetic material.
The present invention solves the above-mentioned problems of the conventional techniques, and an object thereof is to provide a two-part hair cosmetic material which is reduced in the irritating smell due to ammonia, and is good in applicability of a hair cosmetic material obtained by mixing a first agent and a second agent together to the hair, and comb through property. Another object of the present invention is to provide a two-part hair cosmetic material of which emulsified state is stable, and which is reduced in the irritating smell due to ammonia even if it contains ammonia in such an amount that the hair can be sufficiently bleached or dyed with the hair cosmetic material.
Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.